Plate heat exchanger



Aug20, 1968 s. K. JENSSEN ET AL 3,397,742

PLATE HEAT EXCHANGER 4 Sheets-Sheet l Filed Dec. 23, 1965 /NVEA/ros.

y 4 Sheets-Sheet 2 Fig. f5

ffy. f4

S. K. JENSSEN ET AL PLATE HEAT EXCHANGER Aug. 20, 1968 Filed Dec.

.M e www N/Nqs y Mw@ E r/.wn m ver. m NFK r VA. M4 T ne@ sie V/ Aug. 20,196s s. K. JENSSEN ET AL 3,397,742

PLATE HEAT EXCHANG ER Filed Deo. 25, 1965 4 sheets-sheet s Fig, 2/ Fig.22

/zb 7a Aug' 20, 1968 s. K. .JENSSEN ET Al. 3,397,742

PLATE HEAT EXCHANGER 4 Sheets-Sheet 4 Filed Dec, 23, 1965 United StatesPatent O 6 Claims. (l. 16s-167) ABSTRACT OF THE DISCLOSURE Substantiallyidentical heat transfer plates are held sideby-side in a pack to forminterspaces between adjacent plates, the plates being ported and adaptedto coact with marginal packings in the interspaces to define flowchannels for passage of the heat exchange media through the pack; andadjacent plates have spacing projections and supporting surfaces adaptedto abut each other in the interspaces, the projections also formingsupporting surfaces. To enable variations in the spacing betweenadjacent plates, each plate is provided with such spacing projectionsand has its supporting surfaces situated in different planes parallel tothe main plane of the plate; and the projections and supporting surfacesare distributed on the plate in a pattern such that when two adjacentplates are assembled side-by-side (as in the pack of plates) but infirst and then in second relative positions, a spacing projection whichin the lirst relative positions is adapted to abut a supporting surfacesituated in one plane is adapted in the second relative positions toabut a supporting surface situated in a dilerent plane.

The disclosure The present invention relates to plate heat exchangerswith a plurality of identical heat transfer plates of thin pressed sheetmetal, which side by side are kept together to form a pack withinterspaces between adjacent plates limited by packings along the edges,which interspaces form channels for the conducting of the heatexchanging media, distance giving projections from one of the platesbeing in close contact with supporting surfaces on the other plate inthe said interspace. The distance giving projections constitutethemselves at the same time supporting surfaces.

The channels in such a pack get a certain channel characteristic onaccount of the length of the plates and their breadth and mutualdistance which limits the useful magnitude of the flow through them to afairly narrow range. A limited range of flow and a certain heatingsurface per channel means also a locked relationship between the mediumtemperature diderence of the media and their temperature change.

A channel of a considerable length with a small distance between theplates is for instance suitable for giving a small flow a greattemperature change. A large flow that is to be given a smallertemperature change requires a distance between the plates that is largein comparison to the length of the channel in order that the pressurefall will lie within practical limits, and in order that the heatingsurface will not be too large. If the channels in a pack of plates aretoo narrow and too long for a certain purpose so that the pressure fallincreases too much, the latter can certainly be reduced if furtherplates and channels are added to the pack and the total channel area isthus increased, but this brings with it as well that eX- pensive heatingsurface is sacrificed only in order to obtain a depreciation of thepressure fall, and that the heat ice exchanger will get anover-capacity, i.e. gives a too great temperature change.

In order to satisfy at least as nearly as possible such dierent needsone has therefore hitherto been compelled to use plates, which differ atleast as to the height of the distance giving projections so thatdilerent series of such plates form packs with larger or smallerdistances between the plates.

In addition, there is frequently a need to vary the distances betweenthe plates within one and the same pack, for instance when the ows ofthe respective heat eX- changing media are of considerably differentmagnitudes, or in order to change the channel characteristic in somepart of the pack for some other reason, which has been accomplished bymeans of intermingling plates of different shapes in the pack.

The invention aims at obviatng those drawbacks by means of forming thedistance giving projections of identical plates constituting the packsuch that these plates can be put together to make packs with larger orsmaller distances between the plates as well as packs with an optionaldistribution of larger or smaller such distances Within the pack.

The invention is mainly characterized in that each plate is providedwith distance giving projections and has its supporting surfacessituated in different planes parallel to the main plane of the plate,the projections and supporting surfaces being distributed on the platein a pattern, as seen on a front elevation of the plate, such that whentwo such plates are put together so as to cover each other like in thepack of plates, but in different relative positions in other respects,the distance giving projections in the interspace between the plates,which in one relative position lie close to supporting surfaces situatedin one plane, in another relative position will lie closely tosupporting surfaces situated in a different plane, so that differentrelative positions will result in differently large distances betweenthe put together plates.

The invention will be described more in detail below with reference tothe drawings, in which- FIGS. 1 and 2 show a plane View and a sectionalview along line III-III of FIG. 1 respectively, 0f an embodiment of heattransfer plates for conventional heat eX- changers of the kind to whichthe invention relates,

FIG. 3 shows a similar sectional view of a pack of three such plates,

FIGS. 4 and 5 show a plane view and a view of an edge respectively, ofanother embodiment of a heat transfer plate for another conventionalheat exchanger of the kind to which the invention relates,

FIG. 6 illustrates a conventional pack of three such plates showing theedges of the plates,

FIG. 7 illustrates a pack of the same plates, made up according to oneembodiment of the invention,

FIG. 8 illustrates a sectional view of one embodiment of a distancegiving projection impressed in the plate,

FIGS. 9, l0 and l1 show symbols utilized in the following figures forthe same distance giving projection as seen from the left, from the sideand from the right in FIG. 8 respectively,

FIGS. l2 and 13 show a front view and a side View respectively, of apart d of PIG. 1 or 4 pressed according to one embodiment of theinvention,

FIGS. 12x, l2z and 12xz illustrate the same part turned in threedifferent positions,

FIGS. 14, l5 and 16 illustrate like part d of FIG. 3 or 6 each onecombination of plates pressed according to FIG. 12 and put together toform a pack in mutual differently turned positions,

FIGS. 17 and 18 illustrate the impressions according to FIG. 12 on alarger part of the plate on a reduced scale,

FIGS. 19 and 20 illustrate the part d pressed according to anotherembodiment of the invention,

FIGS. 19x, 19y and 19z illustrate the same part, each in a differentlyturned position,

FIGS. 21, 22, 23, 24 and 25 illustrate like the part d of FIG. 3 or 6each one combination of plates pressed according to FIG. 19 and puttogether to form packs in mutual differently turned positions,

FIG. 26 illustrates impressions according to FIG. 19 on a larger part ofthe plate on a reduced scale,

FIGS. 27 :and 28 show a front view and 'a side View respectively, of amodification of the pressing according to FIG. 26,

FIGS. 29 and 30 illustrate the part d pressed according to a furtherembodiment of the invention,

FIGS. 29z 1, 29z 2 and 29z 3 illustrate the same part turned in threediierent positions,

FIGS. 31, 32 and 33 illustrate like part d in FIG. 3 or 6 each onecombination of plates pressed according to FIG. 29 and put together toform packs in mutual dilerently turned positions, and

FIGS. 34 and 35 illustrate a pressing according to FIG. 29 on a largerpart of the plate on a reduced scale.

All the igures are schematical and only intended to serve as examplesWithout limiting the scope. Identical details in the different figuresare provided with .the same reference marks.

In FIGS. 1 and 2, which illustrate a rectangular conventional heattransfer plate, numerals 2, 3, 4 and 5 refer to the edges of the plate,a and b to its respective sides, x and y to the respective center linesof the plates crossing each other in the center point c of the plate,and z (FIG. 2) a line through the center point of the plate andperpendicular to its main plane. The plate is in `addition provided witha port 6 in each of its four corners and with distance givingprojections 7 of the height L, four of Iwhich on each side of the plateare arranged one in each corner of an imaginary square with Ia centerpoint c. When the plates lie together in a pack according to FIG. 3 suchthat they completely cover each other, the distance giving projectionslie close together giving the distance 2L between the plates. An edgepacking 8 around two of the ports of each plate and a packing ring 9around each of the other ports are arranged in the formed interspaces inthe usual way, such that one of the heat exchanging media which is ledthrough two series of ports situated opposite to each other in the pack,is led through every second interspace between the plates, and the otherheat exchanging medium, which is led through the two other series ofsuch ports, is led through the other interspaces.

FIGS. 4 and 5 show a plate that can be regarded as a square part of theplate according to FIG. 1 with the center point c and with equally longedges 2a, 2b, 2c yand 2d. The distances between the plates in a packaccording to FIG. 6 willof lcourse be 2L as well. With edge packings 8aarranged Ias illustrated a similar pack can be utilized for heatexchange in cross-How, one of the heat exchanging media being ledthrough the one interspace in a vertical direction, and the other mediumbeing led through the other interspace in a horizontal direction.

The plates according to FIGS. 1 and 2 can be put together two and two soas to cover each other completely, but with one of the plates turned anyof the following ways in relation to the other unturned plate(O-turned), namely:

(l) X-turned, i.e., turned 180 around the center line x so that edges 2and 4 and sides a and b of the plate exchange their positions,

(2) Y-turned, i.e., turned 180 yaround the center line y so that edges 3and 5 and sides a and b of the plate exchange their positions, and

(3) Z-turned, i.e., turned 180 around line z so that edges 2 and 4 aswell as edges 3 and 5 of the plate but not the sides a and b exchangetheir positions.

The relative positions of the plates may therefore be designated as ohx,o-y and o-z.

'Ihe same applies in connection with square-shaped plates, for instanceaccording to FIGS. 4 and 5, with the further possibility to Z-turn oneof the plates stepwise i.e. to obtain three o-z relative positions, suchthat for instance edge 2a can exchange its position with any of edges2b, 2c or 2d.

The pattern las seen on the plane of the plate, according to which thedistance giving supports are distributed on the plate, has the effect,however, that however relatively positioned the plates are put togethersuch as to cover eachother completely, the distance giving sup-1 portsof adjacent plates Will meet according to FIG. 3 and FIG. 6respectively, so that the distance will remain unvariably 2L. A distanceL can be obtained, however, by displacing one of the plates according toFIG. 7 such that opposite distance giving supports by the side of eachother rest yagainst the adjacent plate. In this changed relativeposition will, as Will be seen, the distance giving supports of the oneplate lie close to supporting surfaces of the other plate, which aresituated in another plane parallel to the main plane of the plate thanthe plane in which the tops of the opposite distance giving supports aresituated, and form corresponding supporting surfaces in the relativeposition according to FIG. 6.

It is the achieving of an effect as described, by chang-y ing therelative positions of identical plates that is the basic idea of thepresent invention. To achieve this eiect by displacing the plates asmentioned lies Within the scope of the invention, but that method bringswith it awkward complications in many cases. Plates according to FIGS. 1and 2, for instance, then get into such relative positions that theports and packings of adjacent plates will not be situated opposite toeach other.

It is therefore 'a particularly important part of the i11- ventionthought to distribute the said distance giving supports and supportingsurfaces according to a pattern such that the effect aimed at can beachieved by means of the dilerent relative positions which are obtainedby X-Y-Z- turnings only, the rectangular or square-shaped plates in allsuch relative positions covering each other completely. Examples of thisare illustrated below with reference to the limited area d of FIGS. 1,3, 4 and 6. Elements 7 thus forming distance giving supports orsupporting surfaces in other planes than the main plane of the plate arethen, according to FIG. 8 presumed to comprise projections 11 formed onthe one side of the plate by means of impressions 10 on the other lsideof the plate. Seen on a front elevation in the drawing the projectionsare marked according to FIG. 9 and the impressions according to FIG. 11.Seen from the side the same element is marked according to FIG. 10.

FIGS. 12 and 13 illustrate the area d of an O-turned plate (o-pla-te)provided with two distance giving projections 7a and 7b lying one ineach of two diagonally opposed corners of a rectangular quadrangle, inthis case a square, with a center point c and forming projections of theheight 2L above side a and side b respectively. In the other cornersmarked with a -lthe supporting points of the plate are situated forsimilar distance giving projections of the adjacent plates. FIG. 12xillustrates the same area of such a plate, X-turned (x-plate). If theo-plate is covered with the x-plate, the distance giving projections 7aof the x-plate will meet the side a of the o-plate at the lowerright-hand cross in FIG. 12 and give the distance 2 L between theplates. If the said x-plate is then covered with an o-plate, thedistance giving projection 7b of the xplate will meet the side b of thiso-plate at the upper lefthand cross of FIG. 12 and give 'the distance 2L between these plates as well. This way a pack of three plates isobtained `with all distances equal to 2L according to FIG.

14. The pack can be extended to any chosen size by adding furtheralternating oand x-plates.

If on the other hand an o-plate is covered with a 180 Z-turned plateaccording to FIG. 122, the distance giving projections 7b ofthe z-plateand the distance giving projections 7a of the o-plate will meet so thatthe distance be tween the plates will be 4L. If this z-plate is thencovered with an o-plate, the distance giving projections 7a of thez-plate will meet the distance giving projections 7b of the said o-plateSo that the distance between these plates will be the addition distance2L+2L=4L as Well. In that way one is able to form packs according toFIG. from alternating oand z-plates with all the distances between theplates equal to 4L.

FIG. 16 gives an example of what packs with optional varying distancesmay look like. Counted from the left in the ligure the tirst distance 2L is, like in FIG. 14, formed by one otand one x-plate. Next distance iswanted to be 4L. This is obtained according to FIG. 15 from one oand onez-plate, but as the one plate in FIG. 16 is an .xplate, the other platemust be a plate that is Z-turned in relation to the x-plate, i.e. anxz-plate according to FIG. 12xz, which may be obtained by firstX-turning an o-plate and then Z-turning the x-plate obtained. Nextdistance is again wanted to be 4L, which is obtained by means of afurther x-plate according to the rule that equal distances in a row willbe formed by alternating plates turned the same way. The last distance2L is formed according to FIG. 14 by means of a further o-plate.

FIG. 17 and 18 give an example of how a great number of such distancegiving projections may be distributed in rows on the plate such thateach projection 7a on the one side a of the plate and a projection 7b onthe other side b of the plate will lie in diametrically opposed cornersof a rectangular quadrangle with a center point c. Those supportingsurfaces in the other corners of the quadrangle are marked with a cross,where the projections of the one plate lie closely against the otherplate, X- or Y-turned.

FIGS. 19 and 20 give in connection with an o plate an example of apattern of distance giving projections by means of which three diierentplate distances may be obtained. Projections 7a and 7b are arranged likein FIG. 12 but have a height of 3L. In addition, there are furtherprojections 12a and 12b at the points marked with a -iin FIG. 12 pressedto the height L above side a and side b, respectively. FIGS. 19x, 19yand 19z show the look of the pattern when turning -to x, yand z-plate,respectively.

If an o-plate is lcovered with a y-plate the projections 7a of they-plate will rest against the bottom of the impression forming theprojection 12b of the o-plate (FIG. 21), and the projection 7a of theo-plate will rest against the bottom of the impression forming theprojection 12b of the y-plate (FIG. 22) such that the distance betweenthe plates will be the subtraction distance 3LL=2L (disregarding thecomparatively small thickness of the sheet). If this y-plate is furthercovered with another o-plate, the projections 7b of the o-plate willproject into the projections 12a of the y-plate (FIG. 21), and theprojections 7b of the y-plate will project into the projections 12a ofthe 0plate (FIG. 22) such that the same distance 2L between the platesis obtained. Using alternating aand y-plates packs can thus be obtainedwith all distances equal to 2L.

Utilizing alternating oand x-plates the projections of diierent heightsof the adjacent plates will rest against each other as shown in FIG. 23such that the addition distances 3L|L=4L arise between the plates.

Utilizing alternating 0- and z-plates, finally, projections 7a and 7b ofthe adjacent plates will, according to FIG. 24, rest against each othersuch that the addition distances 3L+3L=6L arise between the plates.

FIG. 25 gives an example of an optional distribution of the threepossible distances in a pack of plates. Counted` from the left in thefigure, distance 2L is formed between one oand one y-plate according toFIGS. 21 and 22. Next distance 4L is to be formed by a plate that isX-turned in relation to the y-plate, as the relative position must be x6 according to FIG. 23. This will become a z-plate. Next distance of 6Lis formed analogously to FIG. 24 by means of an o-plate, and the enddistance 2L is like Ithe iirst distance formed by means of a y-plate.

FIG. 26 gives an example of how a great number of such distance givingsupports may be distributed in rows on the plate. It differs from FIG.17 only in that the plate at the points of the crosses is provided withdistance giving projections 12a and 12b, respectively. A moditication ofthis arrange-ment consists, according to FIGS. 27 and 28, in that therows of the distance giving projections 12a and 12b, respectively, aresubstituted by ridges 13a and 13b, respectively, which are pressed tothe same height above the neutral plane N of the plate, in which, intheir turn, distance giving elements 7a and 7b, respectively, arepressed `to their height above the neutral plane.

FIGS. 29 yand 30 illustrate an arrangement of distance givingprojections according to the invention, which will be suitable speciallyin connection with packs of squareformed plates, which are able to covereach other with one of the plates Z-turned 90, or 270 in relation to theother, as illustrated by FIGS. 29z 1, 29z 2 and 29z 3, respectively. Inthis case the plate is in three corners of the above-mentionedquadrangle, which in this case will be a square, provided with thedistance giving projections 7b, 12b and 14b, respectively, pressed tothe heights 3L, 2L and L above the one side b of the plate. In therelative positions O-Zl and O-ZZ, the distance giving projection 7b ofthe z-plate meets (according to FIGS. 31 and 32, respectively), theo-plate at its distance giving projections 12b and 14b, respectively,which gives the subtraction distances between the plates 3L-2L=L and3L-L=2L, respectively. In the relative posi'ion O-Z3 the same distancegiving projection meets, according yto FIG. 33, the o-plate in the mainplane, which gives the distance 3L between the plates.

FIGS. 34 and 35 give an example of how a greater number of such distancegiving projections may be distributed in rows on the plate, FIG. 35showing the squares, in the corners of which the distance givingprojections are situated according to the arrangement shown in FIG. 29.

If the plates have some other multigonal shape, for instance havehexagonal or octagonal shape so that they may be Z-turned to 5 and 7different relative positions, respectively, a correspondingly increasednumber of variants of distances may be obtained according to the sameprinciple by means of distributing a correspondingly increased number ofdistance lgiving projections of an equally increased number of heightvariations in the corners of the hexagonal or octagonal platerespectively with a center point c. If the plates are circular thedistance giving projections are distributed along a circle around theircenter point.

Contrary to the preceding arrangements, where the plates haveprojections on their both sides this arrangement will not, however,provide the possibility of olbtaining packs by means of 4turning everysecond plate, in which packs large addition distances arise on accountof the projections of `adjacent plates being oppositely directed likefor instance according to FIGS. 15, 2.3 or 24. Owing to the fact thatthe theoretical possibility of pressing the projections 7b so muchhigher instead might be accompanied by practical difculties, anarrangement according to FIG. 29 is as a rule suitable only inconnection with comparatively small distances.

With the guidance of the examples illustrated and described a personskilled in the art will be able to arrange further modifications. Therelative heights of the distance giving supports may for instance bevaried such that diterent proportions between the varying interspaceswill be obtained. The patterns illustrated in FIGS. 17, 26, 27 and 34may be rearranged in the plane of the plate such as will result if linesx and y change places in the figures, the distance giving projectionsmay have a shape differing from the circular form etc.

We claim:

1. A pla-te heat exchanger having a plurality of substantially identicalheat transfer plates of thin pressed sheets held together inlside-by-side relation in a pack and forming interspaces betweenadjacent plates, said plates having ports and being adapted to coactwith marginal packings in said interspaces to define ow channels forpassage of the heat exchange media through said pack, alternate ones ofsaid interspaces lbeing arranged for passage of one heat exchange mediumand the other interspaces being arranged for passage of the other heatexchange medium, adjacent plates having spacing projections andsupporting surfaces adapted to abut each other in said interspaces, saidprojections forming supporting surfaces, characterized in that eachplate is provided With such spacing projections yand has its supportingsurfaces situated in different planes parallel to the main plane of theplate, said projections and supporting surfaces being -distributed onthe plate -according to a pattern such that when two such adjacentplates are assembled side-by-side, as in the pack of plates, but infirst and then in second `relative positions, a spacing projection whichin said first relative positions is adapted to abut a supporting surfacesituated in one plane is adapted in said second relative positions toabut a supporting surface situated in a different plane, whereby thespacing between the adjacent plates is varied.

2. A plate heat exchanger according to claim 1, in which each plate hasa center point and horizontal and vertical center lines intersecting atthe center point, each plate having on opposite sides a plurality ofsaid projections of maximum and equal height as measured from the mainplane of the plate, a said projection on one side of each plate beinglocated in one corner of an imaginary quadrangle having two pairs ofopposite sides parallel to said horizontal and vertical center lines,respectively, a said projection on the other side of each plate beinglocated in a corner of said quadrangle diametn'cally opposite said onecorner, said quadrangle having a center point coinciding with saidcenter point of the plate, opposite sides of the plate having in theother two corners of the quadrangle, respectively, supporting surfacesfor said projections of maximum height on the adjacent plates, said lastsupporting surfaces being of equal height less than said maximum height.

3. A plate heat exchanger according to claim 2, in which said supportingsurfaces on opposite sides of the plate and in said other two cornersare flush with the respective sides of the plate.

4. A plate heat exchanger according to claim 1, in which each plate hasa -center point and horizontal and vertical center lines intersecting atthe center point, each plate having on opposite sides a plurality ofsaid projections of maximum and equal height as measured from the mainplane of the plate, a said projection on one side of each plate beinglocated in one corner of an imaginary quadrangle having two pairs ofopposite sides parallel to said horizontal and vertical center lines,respectively, a said projection on the other side of each plate beinglocated in a corner of said quadrangle diametrically opposite said onecorner, said quadrangle having a center point coinciding with saidcenter point of the plate, opposite sides of the plate having intheother two corners of the quadrangle, respectively, spacing projectionsof equal height less than said maximum height, each said projection `ofless height being formed by an impression in the opposite side of theplate and of sufficient width to allow a said maximum height projectionof an adjacent plate to project into the impression and rest against itsbottom.

5. A plate heat exchanger according to claim 1, in which each plate hason one side a plurality of said pro- Ijections of different heightsabove said one side and formed by impressions of different depths in theother side, said projections `being distributed in a pattern such thatin said first :relative positions of adjacent plates the highestprojection of one plate rests against the bottom of a said impression ofa certain depth in the adjacent plate, and in said second relativepositions said highest projection rests against the bottom of a saidimpression of a different depth in said ladjacent plate.

6. A plate heat exchanger according to claim 4, in which each saidimpression is elongated to provide a ridge supporting a plurality ofsaid projections of maximum height, each elongated impression beingladapted to receive against its bottom and from an adjacent plate aplurality of said maximum height projections.

References Cited UNITED STATES PATENTS 2,623,736 12/1952 Hytte 165-166 X3,106,242 10/1963 `lenssen etal.

ROBERT A. OLEARY, Primary Examiner.

T. W. STREULE, Assistant Examiner.

